System and method using internal short-circuit conductors to control magnetic wheel adhesion

ABSTRACT

A system and method control magnetic adhesion of a wheel to a surface using internal short-circuit conductors. The method includes providing the wheel having a first disc, apertures retaining magnets, and a conducting ring, and a second disc. In a first configuration, the second disc is isolated from the conducting ring to generate a first magnetic flux to increase adhesion. In a second configuration, magnetic interaction of the second disc and the conducting ring generates a second magnetic flux to decrease adhesion. The system implements the method.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to magnetized wheels, and, moreparticularly, to a system and method using internal short-circuitconductors to control magnetic adhesion of a wheel to a ferromagneticsurface.

BACKGROUND OF THE DISCLOSURE

Magnetic wheels enable vehicles to climb and drive on ferromagneticstructures. For example, an unmanned aerial vehicle (UAV) can fly to apoint on a ferromagnetic structure, perch at that point, and utilizemagnetic wheels to adhere to the ferromagnetic structure. The magneticadhesion is the result of magnetic flux passing through the surface fromthe magnet north pole to the magnetic south pole of a magnet in thewheel. Having a strong magnetic grip to the ferromagnetic surface isessential to prevent the vehicle from disengaging inadvertently and fromfalling from the ferromagnetic surface. However, a strong pulling forceis required to overcome the magnetic adhesion to disengage the vehiclefrom the ferromagnetic surface. In order to enable vehicles to obtain astrong magnetic grip as well as easy disengagement, incorporation of amagnetic switch into the wheel is desirable.

SUMMARY OF THE DISCLOSURE

According to an embodiment consistent with the present disclosure, asystem and method use internal short-circuit conductors to controlmagnetic adhesion of a wheel to a ferromagnetic surface.

In an embodiment, a wheel configured to adhere magnetically to aferromagnetic surface comprises an inner annular disc and a pair ofouter annular discs. The inner annular disc is composed of anon-magnetic material and has a first outer circumferential periphery, afirst central axial bore configured to retain an axle, a plurality ofapertures disposed adjacent to the outer circumferential periphery andconfigured to retain a plurality of magnets, and a conducting ringdisposed adjacent to and surrounding the first central axial bore. Thepair of outer annular discs are composed of a ferromagnetic material andare disposed on either side of the inner annular disc, with each outerannular disc having a second outer circumferential periphery, a secondcentral axial bore configured to retain an axle, an innercircumferential periphery disposed adjacent to the second central axialbore, and an isolator ring composed of a non-magnetic material anddefining a plurality of curves extending in a serpentine mannercircumferentially around the inner circumferential peripheryintermediate of the second outer circumferential periphery and thesecond central axial bore, with the curves of the serpentine isolatorring disposed between the inner circumferential periphery and the secondouter circumferential periphery.

In a first configuration, the curves of the serpentine isolator ring aredisposed in a first position relative to the plurality of magnets tomagnetically isolate the pair of outer discs from the conducting ring,thereby generating a first magnetic flux between the plurality ofmagnets and the ferromagnetic surface to increase the adhesion of thewheel to the ferromagnetic surface. In a second configuration, at leastone outer annular disc is rotated about the axle relative to the innerannular disc to dispose the curves of the serpentine isolator ring in asecond position relative to the plurality of magnets to allow magneticinteraction between the pair of outer discs and the conducting ring,thereby generating a second magnetic flux between the plurality ofmagnets and the ferromagnetic surface to decrease the adhesion of thewheel to the ferromagnetic surface. The second magnetic flux is lessthan the first magnetic flux.

The conducting ring can be composed of steel. Alternatively, theconducting ring can be composed of nickel. In another alternativeembodiment, the conducting ring can be composed of cobalt. The pluralityof magnets can be permanent magnets. Alternatively, the plurality ofmagnets can be electromagnets. The plurality of apertures can becylindrical. The plurality of magnets can be cylindrical.

In another embodiment, a wheel configured to adhere magnetically to aferromagnetic surface comprises a first annular disc and a secondannular disc. The first annular disc is composed of a non-magneticmaterial and has a first outer circumferential periphery, a firstcentral axial bore configured to retain an axle, a plurality ofapertures disposed adjacent to the outer circumferential periphery andconfigured to retain a plurality of magnets, and a conducting ringdisposed adjacent to and surrounding the first central axial bore. Thesecond annular disc is composed of a ferromagnetic material and isdisposed on one side of the first annular disc. The second annular dischas a second outer circumferential periphery, a second central axialbore configured to retain an axle, an inner circumferential peripherydisposed adjacent to the second central axial bore, and an isolator ringcomposed of a non-magnetic material and defining a plurality of curvesextending in a serpentine manner circumferentially around the innercircumferential periphery intermediate of the second outercircumferential periphery and the second central axial bore, with thecurves of the serpentine isolator ring disposed between the innercircumferential periphery and the second outer circumferentialperiphery.

In a first configuration, the curves of the serpentine isolator ring aredisposed in a first position relative to the plurality of magnets tomagnetically isolate the second annular disc from the conducting ring,thereby generating a first magnetic flux between the plurality ofmagnets and the ferromagnetic surface to increase the adhesion of thewheel to the ferromagnetic surface. In a second configuration, thesecond annular disc is rotated about the axle relative to the firstannular disc to dispose the curves of the serpentine isolator ring in asecond position relative to the plurality of magnets to allow magneticinteraction between the second annular disc and the conducting ring,thereby generating a second magnetic flux between the plurality ofmagnets and the ferromagnetic surface to decrease the adhesion of thewheel to the ferromagnetic surface. The second magnetic flux is lessthan the first magnetic flux.

The conducting ring can be composed of steel. Alternatively, theconducting ring can be composed of nickel. In another alternativeembodiment, the conducting ring can be composed of cobalt. The pluralityof magnets can be permanent magnets. Alternatively, the plurality ofmagnets can be electromagnets. The plurality of apertures can becylindrical. The plurality of magnets can be cylindrical.

In a further embodiment, a method of adhering a wheel magnetically to aferromagnetic surface comprises providing a wheel having a first annulardisc and a second annular disc, wherein the first annular disc iscomposed of a non-magnetic material and has a first outercircumferential periphery, a first central axial bore configured toretain an axle, a plurality of apertures disposed adjacent to the outercircumferential periphery and configured to retain a plurality ofmagnets, and a conducting ring disposed adjacent to and surrounding thefirst central axial bore. The second annular disc is composed of aferromagnetic material and is disposed on one side of the first annulardisc. The second annular disc has a second outer circumferentialperiphery, a second central axial bore configured to retain an axle, aninner circumferential periphery disposed adjacent to the second centralaxial bore, and an isolator ring composed of a non-magnetic material anddefining a plurality of curves extending in a serpentine mannercircumferentially around the inner circumferential peripheryintermediate of the second outer circumferential periphery and thesecond central axial bore, with the curves of the serpentine isolatorring disposed between the inner circumferential periphery and the secondouter circumferential periphery.

The method further comprises disposing the first and second annulardiscs in a first configuration wherein the curves of the serpentineisolator ring are disposed in a first position relative to the pluralityof magnets, magnetically isolating the second annular disc from theconducting ring, and generating a first magnetic flux between theplurality of magnets and the ferromagnetic surface thereby increasingthe adhesion of the wheel to the ferromagnetic surface. The methodfurther comprises disposing the first and second annular discs in asecond configuration, wherein the second annular disc is rotated aboutthe axle relative to the first annular disc, disposing the curves of theserpentine isolator ring in a second position relative to the pluralityof magnets, allowing magnetic interaction between the second annulardisc and the conducting ring, and generating a second magnetic fluxbetween the plurality of magnets and the ferromagnetic surface todecrease the adhesion of the wheel to the ferromagnetic surface. Thesecond magnetic flux is less than the first magnetic flux.

The conducting ring can be composed of a ferromagnetic material, such assteel. Alternatively, the conducting ring can be composed of nickel. Inanother alternative embodiment, the conducting ring can be composed ofcobalt. The plurality of magnets can be permanent magnets. The pluralityof magnets can be electromagnets. The plurality of apertures can becylindrical. The plurality of magnets can be cylindrical.

Any combinations of the various embodiments and implementationsdisclosed herein can be used in a further embodiment, consistent withthe disclosure. These and other aspects and features can be appreciatedfrom the following description of certain embodiments presented hereinin accordance with the disclosure and the accompanying drawings andclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a wheel, according to an embodiment.

FIG. 2 is a diagram of the wheel of FIG. 1 with parts separated.

FIG. 3 illustrates outer discs of the wheel of FIG. 1 rotating in acommon direction relative to an inner disc.

FIG. 4 illustrates the outer discs of the wheel of FIG. 1 rotating inopposite directions relative to the inner disc.

FIG. 5 illustrates the inner disc of the wheel of FIG. 1 rotatingrelative to both of the outer discs.

FIG. 6 is a cross-sectional view of the wheel of FIG. 1 in a firstconfiguration.

FIG. 7 illustrates the magnetic flux of the wheel in the firstconfiguration of FIG. 6 along lines 7-7.

FIG. 8 is a cross-sectional view of the wheel of FIG. 1 in a secondconfiguration.

FIG. 9 illustrates the magnetic flux of the wheel in the secondconfiguration of FIG. 8 along lines 9-9.

FIG. 10 is a diagram of an alternative embodiment of the wheel.

FIG. 11 is a diagram of the wheel of FIG. 10 with parts separated.

FIG. 12 is a flowchart of the method of operation of the wheel of FIG. 1.

It is noted that the drawings are illustrative and are not necessarilyto scale.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS OF THE DISCLOSURE

Example embodiments consistent with the teachings included in thepresent disclosure are directed to a system and method using internalshort-circuit conductors to control magnetic adhesion of a wheel to aferromagnetic surface.

Referring to FIGS. 1-9 , the wheel 10 is configured to roll on a surface12. Using the system and method described below, when the surface 12 isferromagnetic, a magnetic flux generated by the wheel 10 can becontrolled to increase or decrease magnetic adhesion of the wheel 10 tothe ferromagnetic surface 12. As shown in FIGS. 1-2 , the wheel 10 hasan inner disc 14 having a pair of planar sides 16. The inner disc 14 iscomposed of a non-magnetic material. For example, the inner disc 14 canbe composed of plastic. The inner disc 14 is generally annular with afirst central axial bore 18 partially surrounded by a disc retainer 20,22 extending perpendicularly from at least one of the planar sides 16.The first central axial bore 18 is configured to receive an axle to rollthe wheel 10 about the axle on the surface 12. A plurality of apertures26 extend perpendicularly and at least partially into at least one ofthe planar sides 16. The plurality of apertures 26 are disposed adjacentto the outer circumferential periphery and configured to retain aplurality of magnets 28. The magnets 28 can be permanent magnets.Alternatively, the magnets 28 can be electromagnets. The magnets 28 aresized and dimensioned to be retained in the respective apertures 26. Inan example embodiment, the apertures 26 are cylindrical, and the magnets28 are also cylindrical. A conducting ring 30 is disposed in an innerperiphery of the inner disc 14. The conducting ring 30 extends aroundthe first central axial bore 18. The conducting ring 30 can be composedof steel. Alternatively, the conducting ring 30 can be composed ofnickel. In another alternative embodiment, the conducting ring 30 can becomposed of cobalt. The conducting ring 30 can also be composed of otherferromagnetic materials.

The wheel 10 also has at least one outer disc 32, 34 disposed adjacentto a respective planar side of the inner disc 14. Each outer disc 32, 34is composed of a ferromagnetic material. For example, each outer disc32, 34 can be composed of steel. Alternatively, each outer disc 32, 34can be composed of nickel. In another alternative embodiment, each outerdisc 32, 34 can be composed of cobalt. The outer discs 32, 34 can alsobe composed of other ferromagnetic materials. Each outer disc 32, 34 hasa central axial bore 36 configured to receive a respective disc retainer20, 22 through which an axle passes. The central axial bore 36 of eachouter disc 32, 34 has a rotation stopper 38 for engaging radial sides40, 42 of a respective disc retainer 20, 22. The radial sides 40, 42limit the rotation of each outer disc 32, 34 relative to the inner disc14 to a predetermined angle. The predetermined angle is equal to180°/(the number of magnets of the inner disc). For example, in anembodiment with eight magnets, the predetermined angle can be about180°/8, which is about 22.5°. Using a different number of magnets wouldchange the predetermined angle. For example, for ten magnets, therotation angle can be about 180°/10, which is about 18°. It is alsounderstood that other sizes and dimensions of the outer diameters of thediscs as well as the aperture sizes are contemplated.

Referring again to FIGS. 1-2 , each outer disc 32, 34 has an outercircumferential periphery 44 and an inner circumferential periphery 46disposed adjacent to the central axial bore 36. An isolator ring 48composed of a non-magnetic material and defining a plurality of curvesextends in a serpentine manner circumferentially around the innercircumferential periphery 46 intermediate of the outer circumferentialperiphery 44 and the central axial bore 36, with the curves of theserpentine isolator ring 48 disposed between the inner circumferentialperiphery 46 and the outer circumferential periphery 44. The isolatorring 48 can be composed of plastic.

As described above, rotation of each outer disc 32, 34 can be performedrelative to the inner disc 14 to within a predetermined angle. FIG. 3illustrates outer discs 32, 34 of the wheel 10 rotating in a commondirection relative to the inner disc 14. As shown in FIG. 3 , the innerdisc 14 can be motionless as the outer discs 32, 34 rotate in a commondirection. FIG. 4 illustrates the outer discs 32, 34 of the wheel 10rotating in opposite directions relative to the inner disc 14. As shownin FIG. 4 , the inner disc 14 can be motionless as the outer discs 32,34 rotate in opposite directions. FIG. 5 illustrates the inner disc 14of the wheel 10 rotating relative to both of the outer discs 32, 34. Asshown in FIG. 5 , the inner disc 14 can be rotated as the outer discs32, 34 remain motionless.

Regardless of the absolute motion of the inner disc 14 and the outerdiscs 32, 34, the relative motion of the discs 14, 32, 34 changes thewheel 10 from a first configuration, as shown in FIGS. 6-7 , to a secondconfiguration, as shown in FIG. 8-9 . In the first configuration, thecurves of the serpentine isolator ring 48 are disposed in a firstposition relative to the plurality of magnets 28 to magnetically isolatethe outer annular discs 32, 34 from the conducting ring 30, therebygenerating a first magnetic flux 50 between the plurality of magnets andthe ferromagnetic surface 12 to increase the adhesion of the wheel tothe ferromagnetic surface 12. A weaker magnetic flux 52 is alsogenerated. An air gap 54 is formed between the inner disc 14 and theferromagnetic surface 12.

In the second configuration, at least one outer annular disc 32, 34 isrotated about the axle relative to the inner annular disc 14 to disposethe curves of the serpentine isolator ring 48 in a second positionrelative to the plurality of magnets 28 to allow magnetic interactionbetween the outer annular discs 32, 34 and the conducting ring 30,thereby generating a second magnetic flux 56 between the plurality ofmagnets 28 and the ferromagnetic surface 12 to decrease the adhesion ofthe wheel 10 to the ferromagnetic surface 12. A stronger magnetic flux58 is also generated between the outer annular discs 32, 34 and theconducting ring 30. However, the second magnetic flux 56 is less thanthe first magnetic flux 50 shown in FIG. 7 , so there is less adhesionof the wheel 10 to the ferromagnetic surface 12 when in this secondposition.

Referring to FIGS. 10-11 , in an alternative embodiment, the wheel 110is configured to roll on a surface 12. When the surface 12 isferromagnetic, a magnetic flux generated by the wheel 110 can becontrolled to increase or decrease magnetic adhesion of the wheel 110 tothe ferromagnetic surface 12. As shown in FIGS. 10-11 , the wheel 110has an inner disc 114 having a pair of planar sides 116. The inner disc114 is composed of a non-magnetic material. For example, the inner disc114 can be composed of plastic. The inner disc 114 is generally annularwith a first central axial bore 118 partially surrounded by a discretainer 120, 122 extending perpendicularly from at least one of theplanar sides 116. The central axial bore 118 is configured to receive anaxle to roll the wheel 110 about the axle on the surface 12. A pluralityof apertures 124, 126 extend perpendicularly and at least partially intoat least one of the planar sides 116. A first plurality of apertures 124are disposed adjacent to the first central axial bore 118 and configuredto retain a first plurality of magnets 128 as inner magnets. A secondplurality of apertures 126 are disposed adjacent to the outercircumferential periphery and configured to retain a second plurality ofmagnets 130 as outer magnets. The magnets 128, 130 are sized anddimensioned to be retained in the respective apertures 124, 126. In anexample embodiment, the apertures 124, 126 are cylindrical, and themagnets 128, 130 are also cylindrical.

The wheel 110 also has at least one outer disc 32, 34 disposed adjacentto a respective planar side of the inner disc 114. Each outer disc 32,34 is composed of a ferromagnetic material. For example, each outer disc32, 34 can be composed of steel. Alternatively, each outer disc 32, 34can be composed of nickel. In another alternative embodiment, each outerdisc 32, 34 can be composed of cobalt. Each outer disc 32, 34 has acentral axial bore 36 configured to receive a respective disc retainer20, 22 through which an axle passes. The central axial bore 36 of eachouter disc 32, 34 has a rotation stopper 38 for engaging radial sides40, 42 of a respective disc retainer 20, 22. The radial sides 40, 42limit the rotation of each outer disc 32, 34 relative to the inner disc114 to a predetermined angle. The predetermined angle is equal to180°/(the number of outer magnets of the inner disc). For example, in anembodiment with eight outer magnets 130, the predetermined angle can beabout 180°/8, which is about 22.5°. Using a different number of outermagnets would change the predetermined angle. For example, for ten outermagnets, the rotation angle can be about 180°/10, which is about 18°. Itis also understood that other sizes and dimensions of the outerdiameters of the discs as well as the aperture sizes are contemplated.

The relative motion of the discs 114, 32, 34 changes the wheel 110 froma first configuration to a second configuration. In the firstconfiguration, the curves of the serpentine isolator ring 48 aredisposed in a first position relative to the second plurality of magnets130 to magnetically isolate the first plurality of magnets 128 from thesecond plurality of magnets 130, thereby generating a first magneticflux between the second plurality of magnets and the ferromagneticsurface 12 to increase the adhesion of the wheel to the ferromagneticsurface 12. In the second configuration, at least one outer annular disc32, 34 is rotated about the axle relative to the inner annular disc 114to dispose the curves of the serpentine isolator ring 48 in a secondposition relative to the second plurality of magnets 130 to allowmagnetic interaction between the first plurality of magnets 128 and thesecond plurality of magnets 130, thereby generating a second magneticflux between the second plurality of magnets 130 and the ferromagneticsurface 12 to decrease the adhesion of the wheel 110 to theferromagnetic surface 12. However, the second magnetic flux is less thanthe first magnetic flux, so there is less adhesion of the wheel 110 tothe ferromagnetic surface 12.

As shown in FIG. 12 , a method 200 includes the step of providing thewheel 10 in step 210, with the wheel 10 having a first annular disc withapertures retaining magnets and a conducting ring, and having a secondannular disc with a serpentine isolator ring. The method 200 thendisposes the first and second annular discs in a first configuration instep 220 with curves of the serpentine isolator ring in a first positionrelative to the magnets. The method 200 then magnetically isolates thesecond annular disc from the conducting ring in step 230. The method 200then generates a first magnetic flux between the magnets and aferromagnetic surface in step 240 to increase the adhesion of the wheelto the ferromagnetic surface. The method 200 then rotates the secondannular disc relative to the first annular disc to be in a secondconfiguration in step 250, and disposes the curves of the serpentineisolator ring in a second position in step 260. The method 200 thenallows magnetic interaction between the second annular disc and theconducting ring in step 270, and generates a second magnetic fluxbetween the magnets and the ferromagnetic surface in step 280, with thesecond magnetic flux being less than the first magnetic flux. The method200 then decreases the adhesion of the wheel to the ferromagneticsurface in step 290.

Portions of the methods described herein can be performed by software orfirmware in machine readable form on a tangible (e.g., non-transitory)storage medium. For example, the software or firmware can be in the formof a computer program including computer program code adapted to causethe system to perform various actions described herein when the programis run on a computer or suitable hardware device, and where the computerprogram can be embodied on a computer readable medium. Examples oftangible storage media include computer storage devices havingcomputer-readable media such as disks, thumb drives, flash memory, andthe like, and do not include propagated signals. Propagated signals canbe present in a tangible storage media. The software can be suitable forexecution on a parallel processor or a serial processor such thatvarious actions described herein can be carried out in any suitableorder, or simultaneously.

It is to be further understood that like or similar numerals in thedrawings represent like or similar elements through the several figures,and that not all components or steps described and illustrated withreference to the figures are required for all embodiments orarrangements.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “contains”,“containing”, “includes”, “including,” “comprises”, and/or “comprising,”and variations thereof, when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Terms of orientation are used herein merely for purposes of conventionand referencing and are not to be construed as limiting. However, it isrecognized these terms could be used with reference to an operator oruser. Accordingly, no limitations are implied or to be inferred. Inaddition, the use of ordinal numbers (e.g., first, second, third) is fordistinction and not counting. For example, the use of “third” does notimply there is a corresponding “first” or “second.” Also, thephraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” “having,” “containing,” “involving,” andvariations thereof herein, is meant to encompass the items listedthereafter and equivalents thereof as well as additional items.

While the disclosure has described several exemplary embodiments, itwill be understood by those skilled in the art that various changes canbe made, and equivalents can be substituted for elements thereof,without departing from the spirit and scope of the invention. Inaddition, many modifications will be appreciated by those skilled in theart to adapt a particular instrument, situation, or material toembodiments of the disclosure without departing from the essential scopethereof. Therefore, it is intended that the invention not be limited tothe particular embodiments disclosed, or to the best mode contemplatedfor carrying out this invention, but that the invention will include allembodiments falling within the scope of the appended claims.

The subject matter described above is provided by way of illustrationonly and should not be construed as limiting. Various modifications andchanges can be made to the subject matter described herein withoutfollowing the example embodiments and applications illustrated anddescribed, and without departing from the true spirit and scope of theinvention encompassed by the present disclosure, which is defined by theset of recitations in the following claims and by structures andfunctions or steps which are equivalent to these recitations.

What is claimed is:
 1. A wheel configured to adhere magnetically to aferromagnetic surface, comprising: an inner annular disc composed of anon-magnetic material and having: a first outer circumferentialperiphery; a first central axial bore configured to retain an axle; aplurality of apertures disposed adjacent to the outer circumferentialperiphery and configured to retain a plurality of magnets; and aconducting ring disposed adjacent to and surrounding the first centralaxial bore; and a pair of outer annular discs composed of aferromagnetic material and disposed on either side of the inner annulardisc, with each outer annular disc having: a second outercircumferential periphery; a second central axial bore configured toretain an axle; an inner circumferential periphery disposed adjacent tothe second central axial bore; and an isolator ring composed of anon-magnetic material and defining a plurality of curves extending in aserpentine manner circumferentially around the inner circumferentialperiphery intermediate of the second outer circumferential periphery andthe second central axial bore, with the curves of the serpentineisolator ring disposed between the inner circumferential periphery andthe second outer circumferential periphery, wherein in a firstconfiguration, the curves of the serpentine isolator ring are disposedin a first position relative to the plurality of magnets to magneticallyisolate the pair of outer discs from the conducting ring, therebygenerating a first magnetic flux between the plurality of magnets andthe ferromagnetic surface to increase the adhesion of the wheel to theferromagnetic surface, and wherein in a second configuration, at leastone outer annular disc is rotated about the axle relative to the innerannular disc to dispose the curves of the serpentine isolator ring in asecond position relative to the plurality of magnets to allow magneticinteraction between the pair of outer discs and the conducting ring,thereby generating a second magnetic flux between the plurality ofmagnets and the ferromagnetic surface to decrease the adhesion of thewheel to the ferromagnetic surface, wherein the second magnetic flux isless than the first magnetic flux.
 2. The wheel of claim 1, wherein theconducting ring is composed of a ferromagnetic material selected fromthe group consisting of steel, nickel, and cobalt.
 3. The wheel of claim1, wherein the plurality of magnets are permanent magnets.
 4. The wheelof claim 1, wherein the plurality of magnets are electromagnets.
 5. Thewheel of claim 1, wherein the plurality of apertures are cylindrical. 6.The wheel of claim 5, wherein the plurality of magnets are cylindrical.7. A wheel configured to adhere magnetically to a ferromagnetic surface,comprising: a first annular disc composed of a non-magnetic material andhaving: a first outer circumferential periphery; a first central axialbore configured to retain an axle; a plurality of apertures disposedadjacent to the outer circumferential periphery and configured to retaina plurality of magnets; and a conducting ring disposed adjacent to andsurrounding the first central axial bore; and a second annular disccomposed of a ferromagnetic material and disposed on one side of thefirst annular disc, with the second annular disc having: a second outercircumferential periphery; a second central axial bore configured toretain an axle; an inner circumferential periphery disposed adjacent tothe second central axial bore; and an isolator ring composed of anon-magnetic material and defining a plurality of curves extending in aserpentine manner circumferentially around the inner circumferentialperiphery intermediate of the second outer circumferential periphery andthe second central axial bore, with the curves of the serpentineisolator ring disposed between the inner circumferential periphery andthe second outer circumferential periphery, wherein in a firstconfiguration, the curves of the serpentine isolator ring are disposedin a first position relative to the plurality of magnets to magneticallyisolate the second annular disc from the conducting ring, therebygenerating a first magnetic flux between the plurality of magnets andthe ferromagnetic surface to increase the adhesion of the wheel to theferromagnetic surface, and wherein in a second configuration, the secondannular disc is rotated about the axle relative to the first annulardisc to dispose the curves of the serpentine isolator ring in a secondposition relative to the plurality of magnets to allow magneticinteraction between the second annular disc and the conducting ring,thereby generating a second magnetic flux between the plurality ofmagnets and the ferromagnetic surface to decrease the adhesion of thewheel to the ferromagnetic surface, wherein the second magnetic flux isless than the first magnetic flux.
 8. The wheel of claim 7, wherein theconducting ring is composed of a ferromagnetic material selected fromthe group consisting of steel, nickel, and cobalt.
 9. The wheel of claim7, wherein the plurality of magnets are permanent magnets.
 10. The wheelof claim 7, wherein the plurality of magnets are electromagnets.
 11. Thewheel of claim 7, wherein the plurality of apertures are cylindrical.12. The wheel of claim 11, wherein the plurality of magnets arecylindrical.
 13. A method of adhering a wheel magnetically to aferromagnetic surface, comprising: providing a wheel having a firstannular disc and a second annular disc, wherein the first annular discis composed of a non-magnetic material and has: a first outercircumferential periphery; a first central axial bore configured toretain an axle; a plurality of apertures disposed adjacent to the outercircumferential periphery and configured to retain a plurality ofmagnets; and a conducting ring disposed adjacent to and surrounding thefirst central axial bore; and wherein the second annular disc iscomposed of a ferromagnetic material and disposed on one side of thefirst annular disc, with the second annular disc having: a second outercircumferential periphery; a second central axial bore configured toretain an axle; an inner circumferential periphery disposed adjacent tothe second central axial bore; and an isolator ring composed of anon-magnetic material and defining a plurality of curves extending in aserpentine manner circumferentially around the inner circumferentialperiphery intermediate of the second outer circumferential periphery andthe second central axial bore, with the curves of the serpentineisolator ring disposed between the inner circumferential periphery andthe second outer circumferential periphery; disposing the first andsecond annular discs in a first configuration wherein the curves of theserpentine isolator ring are disposed in a first position relative tothe plurality of magnets; magnetically isolating the second annular discfrom the conducting ring; and generating a first magnetic flux betweenthe plurality of magnets and the ferromagnetic surface therebyincreasing the adhesion of the wheel to the ferromagnetic surface. 14.The method of claim 13, further comprising: disposing the first andsecond annular discs in a second configuration, wherein the secondannular disc is rotated about the axle relative to the first annulardisc; disposing the curves of the serpentine isolator ring in a secondposition relative to the plurality of magnets; allowing magneticinteraction between the second annular disc and the conducting ring; andgenerating a second magnetic flux between the plurality of magnets andthe ferromagnetic surface to decrease the adhesion of the wheel to theferromagnetic surface, wherein the second magnetic flux is less than thefirst magnetic flux.
 15. The method of claim 13, wherein the conductingring is composed of a ferromagnetic material.
 16. The method of claim15, wherein the conducting ring is composed of a ferromagnetic materialselected from the group consisting of steel, nickel, and cobalt.
 17. Themethod of claim 13, wherein the plurality of magnets are permanentmagnets.
 18. The method of claim 13, wherein the plurality of magnetsare electromagnets.
 19. The method of claim 13, wherein the plurality ofapertures are cylindrical.
 20. The method of claim 18, wherein theplurality of magnets are cylindrical.